Can only boot in Safe mode, then get beeps

I urgently need help on this problem. My PC won't boot. Instead it first displays the Windows XP splash screen and then shows a message stating, "We apologize.....but Windows did not start successfully....". Then it gives me the option to start under various alternative states: safe mode, use of last successful settings, etc. I tried each of those, but I only was able to boot in Safe mode with constant beeps.

When my system last worked "properly" I was having problems with my DVD burner. I replaced it with the current Pioneer. When I reassembled everything, I got a steady, continuous beep, beep, beep, beep, beep, beep, etc.

I went to my other system and researched beep alarms and determined that I had a power problem. I then rechecked all my power supply connections.

Windows would not boot
After I rechecked all my power connections, and after finding that the beeps continued, I attempted some trouble-shooting (perhaps right down through my foot!). I detached all of the CD, floppy and DVD drives and powered up. At that point Windows would not boot. I reattached the same drives, checked the power connections, powered up again, and still no success.

BEEPs continued in Safe Mode
I was able to reboot in Safe mode, but, when I did, the beeps started up again.